328M 5er odd swaying

[Ynot4me2]

I wonder if raising the TH or lowering the TV to get that TH nose lower would be beneficial? Right now, with his garage empty, he is running nose high.

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[Old_BANE]

Have you tried towing with the auto level disengaged? The 2500 with air ride and the springs in the back get a little wonky with shifting weight loads while traveling. That could explain your issues up hills because your pin weight is going to change and your leveling system will try to accommodate. Lots of RAM owners over at HD Rams had issues with anything over 1500 lbs pin on the air suspension and general concensus was about 2k lbs being the comfortable limit for the auto level.

I actually did the day I picked it up. Couldn’t have been enough sway to be memorable, but there was a lot going on towing it for the first time. I’ll experiment with both settings on the way home this week.

I do not want to start the truck debate since there are many threads that cover that topic, have you considered that your problem may be caused by your truck. Your truck should be about maxed out. Do you know anyone with a different truck to tow your trailer to see if they have the same problem? If they do have the same problem then you can concentrate on the trailer. If the sway problem is caused by the truck then trying to correct the problem by changing things in the trailer may not produce the desired results.

You also mention that you have the picture frame adapter for the Ram puck system. Is there any possibility that is contributing to the problem?

To your point, I can’t rule out the truck. I’m skeptical since I’ve pulled with nearly the same truck previously with no issues. Granted, that truck didn’t have the air ride suspension.

The picture frame adapter is definitely contributing to the nose-high attitude of the trailer, though I can’t say with any confidence that it is causal or contributing to the sway. The only thing I can do there is get a different hitch or pin box; that may be a last resort.

Sway in not just generated by one aspect. With a toy in the garage he stated it is better, not no sway, but better. Better is because the mass in the garage now move the effective center of gravity lower. The lower the center of gravity, the more stable. The OP is trying to get a balanced experience but he is also trying to accommodate little to no freeboard in payload. So probably will never achieve complete comfort that is desired, but by shifting weight depending how they are camping that trip will make a huge difference. Getting some 40-50# sacks of sand or weights from the home gym and some trial and error will figure out how much more is needed to make the difference in feel, and then the OP will have to come to terms with the payload.

I do have a couple Bowflex select tech dumbbells I could use to add 100# under the master bed…

Thank you for the continued explanation. He may have issues with adding more weight though, since from what I can tell, he is at, or over, his GVWR for the trailer. He said he is at 20% pin weight at 2920 lbs. and a GVWR of 14, 400 lbs. And that is without the motorcycle in the garage. It looks like he's about 1,000 lbs. over his GVWR.

I'm not a member of the weight police, but one does have to wonder if he may expecting a bit too much from the 3/4 ton truck. IMO, 15,000 lbs. is getting pretty much into dually territory.

Good point, the truck is nearly maxed out. Though the GAWRs aren’t. Funny the axles are rated to a higher total than the GVWR. But to my previous experience with a similar truck and trailer setup, same weights/length just no air ride suspension, never saw sway before now.

I'm new to this group, but am active on the HD RAM's forum and as Texas Yankee mentioned above this has been discussed as a concern with the 2500 air suspension. I believe part of the discussion was the air suspension bags being mounted further inboard (toward the center of the truck axle) than leafs for other trucks such as the RAM 3500. The end result was less side to side stability. I didn't do all the math on the OP's original post, but his pin weight seems to be pretty high for a 2500 truck. Couple that kind of pin weight with the uniqueness of the 2500 air suspension and things could get a little dicey. I run a similar pin weight with my 2930RL and RAM 3500 with rear air assist and its very stable towing. The air on the 3500 is a totally different setup though and uses traditional air bags with a lighter duty leaf spring pack. In that case, the bags simply assist a traditional leaf spring setup.

Thanks for the tip; I’ll do some sleuthing on the air suspension. Also found this while double checking weight capacities on the truck: RAM recommends only 15% pin weight for 5th wheels…



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[huntindog]

I actually did the day I picked it up. Couldn’t have been enough sway to be memorable, but there was a lot going on towing it for the first time. I’ll experiment with both settings on the way home this week.


To your point, I can’t rule out the truck. I’m skeptical since I’ve pulled with nearly the same truck previously with no issues. Granted, that truck didn’t have the air ride suspension.

The picture frame adapter is definitely contributing to the nose-high attitude of the trailer, though I can’t say with any confidence that it is causal or contributing to the sway. The only thing I can do there is get a different hitch or pin box; that may be a last resort.


I do have a couple Bowflex select tech dumbbells I could use to add 100# under the master bed…


Good point, the truck is nearly maxed out. Though the GAWRs aren’t. Funny the axles are rated to a higher total than the GVWR. But to my previous experience with a similar truck and trailer setup, same weights/length just no air ride suspension, never saw sway before now.


Thanks for the tip; I’ll do some sleuthing on the air suspension. Also found this while double checking weight capacities on the truck: RAM recommends only 15% pin weight for 5th wheels…



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Only 15%? That is interesting. Is that % only for the 2500s with the Air Suspension? Do other Ram models have the more traditional 20-25% recommendation? If so, that coiuld be the red herring.

[Wileykid]

Only 15%? That is interesting. Is that % only for the 2500s with the Air Suspension? Do other Ram models have the more traditional 20-25% recommendation? If so, that coiuld be the red herring.

The J2807_201602 test standards that all the manufacturers use specifies a minimum pin weight of 15% (section 4.4.3). With that, and most using a flatbed type trailer for testing, marketing at its best.

I have a 320G, that also has a very light pin weight. Anything below around 17-18% pin weight will result in sway at times. Not to be the weight police, but the high pin weight for a 3/4 ton truck, and the RAM 2500 being geared more for comfort, a 1 ton anything would solve most of the problems.

SAE standards: https://fifthwheelst.com/documents/t...ds-2016-02.pdf
There is a revised 2020 version, but could not get it without paying for the doc, and doubt what we are talking here is different.

[goducks14]

Not enough truck and the coils are not nearly as solid as leafs. BTDT. We had a 12 Ram 2500 CTD and towed a smaller 28' 9200 lb 5th wheel for six years with it. Then we got a 2018 Ram 2500 6.4 (Emission stuff on the 12 was the killer) in the same configuration, CC, LB, 4x4. With the 12 Ram CTD 2500 the combo was about as solid as a train on rails. Not so much with the 18 2500 6.4 Hemi. It always felt a little like the 5er and truck were slightly not in sync. It wouldn't track as solid and wind and semi's seemed to affect it more.
When I had the gas Ram I found a company that makes a different style trackbar for the rear. They show how the Rams coils oscillates when going up and down making the rear axle move sideways. They hung a plumb line down and used a lift to show the amount of side to side rear diff movement with the OEM trackbar then installed the Thuren and repeated the same test and there was hardly any side to side rear diff movement. Where the movement happens is when the trucks rear suspension is compressed more, e.g, heavy pin weight.
This video isn't the same one as I can't seem to find it but it does show and talk about replacing the OEM trackbar.

https://www.youtube.com/watch?v=PGEWqmo-pNo

I will say again that that 2500 is not enough truck for that TH mainly from the Ram rear suspension standpoint. The trucks maxed out on RAWR as well. The couple that with a top heavy TH and the rear coils are asked to do too much.

[Old_BANE]

The J2807_201602 test standards that all the manufacturers use specifies a minimum pin weight of 15% (section 4.4.3). With that, and most using a flatbed type trailer for testing, marketing at its best.

I have a 320G, that also has a very light pin weight. Anything below around 17-18% pin weight will result in sway at times. Not to be the weight police, but the high pin weight for a 3/4 ton truck, and the RAM 2500 being geared more for comfort, a 1 ton anything would solve most of the problems.

SAE standards: https://fifthwheelst.com/documents/t...ds-2016-02.pdf
There is a revised 2020 version, but could not get it without paying for the doc, and doubt what we are talking here is different.

A fair point. Though now I wonder if GD planned the TH to have heavy pin weights unloaded, so that when the garage is loaded and the pin lightens, that it stays above 15%?


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[Hoopy Frood]

Almost all toyhaulers are designed to have a heavier than normal pin weight unloaded. Otherwise the pin weight would get too light when a thousand, or more, pounds were loaded into the garage.

[goducks14]

Hoping someone has some new ideas for me. Been researching 5th wheel sway problems for a while and tried most everything I’ve found. But I still get some odd sway issues.

Specifically, nearly anytime I’m climbing a hill, big or small, a get it with anything more than neutral throttle. It happens everywhere between 40-80mph, partial to full throttle, yet only while accelerating uphill. It stops when I lift off, sometimes a slight lift will arrest it, others I have to completely lift off. And the trailer tow brake trick doesn’t work. Never get it while passing or being passed by semi trucks, and never downhill. One time it swayed so bad going up a pass at 45mph it tripped the stability control!

TV: 2016 Ram 2500 CCLB Laramie with the air suspension, towed at the Alt Trailer Height, Superglide hitch with the picture frame adapter for the Ram puck system, tires at 65psi front, 80 psi rear per sticker

Coach: 2018 328M with brand new 7k# springs, MORyde CRE3000, and HD wet bolt kit, tires at 110psi per sticker

It swayed before the suspension upgrade as well. This is with an empty garage and tanks. Sometimes I haul my 440# motorcycle plus tools to the track and it actually sways less with the extra weight in the back.

Hit the scales today on the way out on a family trip and I’ve got 2920# on the pin which is 20% without the bike (14400# trailer GVW). As I understand it, that’s the sweet spot and more weight on the pin should help stop sway, not less.

I read the other posts about the 320g and SRW vs DRW. If DRW was an option for me I’d do it with confidence it would likely solve my issue. But that’s not going to work for me so I have to try to solve it with what I’ve got. My next step is to load the fresh water tank before heading home next week to see if that helps. After that I’m considering adding shocks to the suspension. My rig does ride noise high a bit, but it doesn’t look gross to me and shouldn’t be causing this much problems.

I’m at a loss here. Had a similar 35’ TH before, 2016 Keystone Impact 311, with almost this exact truck (just a lower trim work truck) and that never swayed. Love my Momentum but having to lift off the throttle to stop sway while climbing mountain passes, or just overpasses, is too much!

Thoughts?


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So did you unhook and weigh the trucks rear axle separately?

[Old_BANE]

I have weighed everything but the front axle by itself. The rear axle loaded is 6540#; GAWR is 6500#. So yes, I’m overloaded by 40# with a full tank of diesel and a 25# propane tank in the bed.

Empty the rear axle is 3620#


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[Wileykid]

I have no problems running a truck at its designed weight limits, but some are better than others. About the only thing I would try is a bigger sway bar. Like someone mentioned earlier, the RAM air suspension/coils allow a fair amount of movement, which could contribute to your problem. Why you had no problem with your last trailer, don't know. There is a reason Ford/Chevy, and even RAM (on the 3500) have stayed with leaf springs on the HD's.

I don't think you need to go to a DRW unless you wanted to. Ideal would be a 3500 SRW long bed. That would handle the trailer.